In an internal combustion engine such as a diesel engine, exhaust gas recirculation control is an important issue from the viewpoint of cleaning exhaust gas, in particular, cutting emissions of nitrogen oxides. Known exhaust gas recirculation devices are designed to control the opening of an exhaust gas recirculation valve so as to provide a predetermined exhaust gas recirculation ratio as disclosed in, e.g., JP-A-2003-83034, Japanese Patent No. 3329711, and JP-A-2003-516496.